In the computing industry, it is quite common to transfer data and commands between a plurality of data processing devices, such as computers, printers, displays, terminals, and other network resources. Interconnection of computers and other peripheral devices principally developed in the early 1970's with the advent of computer networking systems which permitted the distribution of access to computing resources beyond the immediate proximity of a mainframe computer.
Recently, "local area networks" (LANs) have been developed which allow transfer of data between a localized set of computing and peripheral devices, typically in the same geographical area such as one building or a plurality of buildings closely situated together. Examples of such LANs may be found in U.S. Pat. Nos. 4,063,220, 4,661,902, and 4,689,786.
In the APPLETALK (R) (a trademark of Apple Computer, Inc.) network system, each "node" or computer, printer, peripheral, and other network resources share resources with a file server. The file server includes three main APPLETALK protocols called the APPLETALK Filing Protocol (AFP), APPLETALK Session Protocol (ASP), and the operating system of the file server includes the APPLETALK Transaction Protocol (ATP). The AFP is a protocol dealing with issues that are file system related. The AFP uses the ASP to receive file system requests from network entities and to send responses back to the entities. The request and responses may be partitioned into smaller data packets and the ASP uses the ATP to send and receive these data packets over the network.
The ASP is a protocol for maintaining network sessions between the file server and the network entities. A session is opened once an entity establishes communication with the server. The ASP keeps information about the entity in a session object
In the APPLETALK network system, each entity is assigned a unique 8-bit identifier which allowed the entity to filter out transmissions directed to other entities. Since the 8 bit identifier, or entity ID, was 8 bits in length, the number of entities or computers and peripherals and other network resources in the LAN was limited to 256 (this number is less the values where all the bits are set and all of the bits are clear, which are reserved). This limits the utility of such LANs, since an expansion beyond the 256 node limit required the connection of additional hardware to the system, such as another file server, for example. This results in an increase of the complexity of the local area network, as well as an increase in its cost.
U.S. Pat. No. 5,150,464, entitled "Local Area Network Device Start Up Process" and U.S. Pat. No. 5,150,464, entitled "Network Device Location" are both directed to systems for extending the number of entities a network can support. Even though these systems operate effectively for their intended purpose, they are both directed to extending the use of a network by adding routers and allowing the network to be connected to other network systems. What is needed therefore is a system and method in which more users can be served at one time by one file server on such a network. The system must be easily implemented in an existing network system. In addition, the system should easily support use by the networks. The present invention addresses such a need.